U.S. patent number 10,974,710 [Application Number 16/691,122] was granted by the patent office on 2021-04-13 for watertight chamber type electric vacuum pump and vacuum boosting brake system.
This patent grant is currently assigned to Hyundai Motor Company, Kia Motors Corporation. The grantee listed for this patent is Hyundai Motor Company, Kia Motors Corporation. Invention is credited to Jae-Won Jeong, Byoung-Soo Yoo.
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United States Patent |
10,974,710 |
Jeong , et al. |
April 13, 2021 |
Watertight chamber type electric vacuum pump and vacuum boosting
brake system
Abstract
An electric vacuum pump applied to a vacuum boosting brake
system is provided. The pump has a water containing capacity that
is greater than a backflow water capacity of an internal space
defined in a pump housing which forms vacuum pressure. The pump
includes a watertight chamber that is coupled to an exhaust port of
a pump housing.
Inventors: |
Jeong; Jae-Won (Gyeonggi-do,
KR), Yoo; Byoung-Soo (Incheon, KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
Hyundai Motor Company
Kia Motors Corporation |
Seoul
Seoul |
N/A
N/A |
KR
KR |
|
|
Assignee: |
Hyundai Motor Company (Seoul,
KR)
Kia Motors Corporation (Seoul, KR)
|
Family
ID: |
1000005483650 |
Appl.
No.: |
16/691,122 |
Filed: |
November 21, 2019 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20200262406 A1 |
Aug 20, 2020 |
|
Foreign Application Priority Data
|
|
|
|
|
Feb 15, 2019 [KR] |
|
|
10-2019-0017959 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60T
17/02 (20130101) |
Current International
Class: |
B60T
17/02 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
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10-2016-0082605 |
|
Jul 2016 |
|
KR |
|
Primary Examiner: Lopez; F Daniel
Attorney, Agent or Firm: Mintz Levin Cohn Ferris Glovsky and
Popeo, P.C. Corless; Peter F.
Claims
What is claimed is:
1. An electric vacuum pump, comprising: a watertight chamber
coupled to an exhaust port of a pump housing, the electric vacuum
pump forming a vacuum pressure, wherein the watertight chamber has
an arc-shaped side surface so that the watertight chamber abuts a
cylindrical body of the pump housing.
2. The electric vacuum pump of claim 1, wherein the watertight
chamber has a water containing capacity greater than a backflow
water capacity of in an internal space defined in the pump
housing.
3. The electric vacuum pump of claim 1, wherein the watertight
chamber includes: a chamber body having the water containing
capacity; and a connection port protrudes from the chamber body and
an extension hose that extends from the connection port and
connects to the exhaust port to integrate the watertight chamber
with the pump housing.
4. The electric vacuum pump of claim 3, wherein the connection port
has a bent structure corresponding to an inclination angle of the
exhaust port.
5. The electric vacuum pump of claim 3, wherein the extension hose
is fitted into the exhaust port.
6. The electric vacuum pump of claim 3, wherein the extension hose
is threadedly coupled with the exhaust port.
7. The electric vacuum pump of claim 1, wherein the pump housing
includes: a port flange into which the exhaust port is penetrated;
and an intake port penetrated into the port flange and configured
to suction air to form a degree of vacuum at a position different
from a position of the exhaust port.
8. The electric vacuum pump of claim 7, wherein a pump cap is
coupled to the port flange, and a vane is disposed in an internal
space of the pump cap to rotate the vane by a motor to form the
degree of vacuum.
9. The electric vacuum pump of claim 8, wherein the motor is
disposed under the port flange and coupled with the vane by a motor
shaft.
10. The electric vacuum pump of claim 9, wherein the motor is
coupled with a pump controller, and the pump controller is disposed
under the motor to drive the motor.
11. The electric vacuum pump of claim 10, wherein the pump
controller is protected from an outside by a pump cover coupled to
a lower side of the pump housing.
12. The electric vacuum pump of claim 11, wherein a connector port
of the pump cover connects a power supply and a signal line to the
pump controller.
13. A vacuum boosting brake system, comprising; the electric vacuum
pump of claim 1; and a vacuum hose that couples a brake booster
with the electric vacuum pump.
14. The vacuum boosting brake system of claim 13, wherein the
vacuum hose is coupled to an intake port of the electric vacuum
pump.
15. The vacuum boosting brake system of claim 14, wherein the
intake port includes a check valve configured to unidirectionally
form a vacuum pressure in the vacuum hose.
Description
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to Korean Patent Application No.
10-2019-0017959, filed on Feb. 15, 2019, which is incorporated
herein by reference in its entirety.
BACKGROUND
Field of the Invention
The present invention relates to an electric vacuum pump, and, more
particularly, to a vacuum boosting brake system that uses a
watertight chamber type electric vacuum pump omitting a separate
watertight retaining device even in an engine mounting structure
having an insufficient watertight position.
Description of Related Art
Generally, an electric vacuum pump (EVP) is operated by an electric
motor to generate vacuum pressure, and is used together with a
vacuum boosting brake system of a turbo vehicle or a vehicle having
insufficient brake negative pressure. Particularly, in the
operation of a vacuum boosting type brake applied to vehicles, when
vacuum pressure for brake boosting is insufficient, the force with
which a driver engages a pedal is insufficient to generate
sufficient braking force, and thus, vacuum pressure generated from
an engine is used, and also insufficient vacuum pressure is
required to be supplemented by the operation of the EVP using
electricity.
Particularly, compared to a mechanical vacuum pump which is
directly installed in a main body of an engine and engages with an
engine shaft to operate together with the engine whereby fuel
efficiency reduces due to an increase in engine drag, the EVP is
advantageous in that the fuel efficiency is enhanced. Therefore,
the EVP is mainly used to secure braking force of the vacuum
boosting type brake when braking.
However, the EVP is sensitive to watertightness due to
characteristics of being electrically operated. Moreover, since the
EVP is installed around the engine, a failure in watertightness
leads to damage to a vane. In addition, since the EVP is connected,
along with an electric wiring line, to a communication line of a
controller area network (CAN) for a chassis, a failure occurring in
the EVP induces a failure in the entirety of a chassis
controller.
Particularly, in the EVP, after a motor rotation interruption
signal of the EVP controller is generated, a predetermined amount
of water is reabsorbed by suction of the atmospheric air through an
outlet by inertia rotation and reverse rotation of the motor,
whereby an EVP outlet immersion event in which the motor is
immersed in water occurs. Accordingly, in the EVP, the vane made of
carbon material is damaged by reabsorbed water, and thus, the
controller short-circuits due to contact with water, whereby a
chassis CAN failure occurs and thus the entirety of the chassis
controller coupled to the chassis CAN may malfunction.
Therefore, the EVP is designed with a snorkeling hose apparatus
mounted to an air outlet portion to increase the height of the air
outlet to a position at which it is not immersed in water, thus
overcoming disadvantages in installation position. However, the
application of this scheme causes structural problems and also an
increase in the production cost.
SUMMARY
The present invention is directed to an electric vacuum pump and a
vacuum boosting brake system which employs a watertight chamber.
Therefore, even when the electric vacuum pump is installed at an
insufficient watertight position, the watertightness is possible,
and therefore, the production cost and the weight may be reduced by
removing a typical snorkeling hose apparatus. Particularly, even
when water is reversely suctioned by inertia rotation and reverse
rotation of a motor after a motor rotation interruption signal is
generated, water penetration may be prevented and blocked by the
air pressure and volume of the watertight chamber, whereby even
when the electric vacuum pump is immersed in water, an internal
electric circuit may be prevented from being damaged.
Other objects and advantages of the present invention may be
understood by the following description, and become apparent with
reference to the exemplary embodiments of the present invention.
Also, it is obvious to those skilled in the art to which the
present invention pertains that the objects and advantages of the
present invention can be realized by the means as claimed and
combinations thereof.
In accordance with an exemplary embodiment of the present
invention, an electric vacuum pump may include a watertight chamber
coupled to an exhaust port of a pump housing that forms a vacuum
pressure. In addition, the watertight chamber may have an open
structure to allow water to be drawn thereinto. The watertight
chamber may have a water containing capacity greater than a
backflow water capacity of an internal space defined in the pump
housing. Additionally, the watertight chamber may have an
arc-shaped side surface to allow the watertight chamber to be
proximate to a cylindrical body of the pump housing.
In an exemplary embodiment, the watertight chamber may include a
chamber body having water containing capacity, and a connection
port disposed on the chamber body and coupled with the exhaust port
to integrate the watertight chamber with the pump housing. The
connection port may include a chamber port that protrudes from the
chamber body, and an extension hose that extends from the chamber
port or is fitted into the exhaust port. The pump housing may
include a port flange into which the exhaust port is penetrated,
and an intake port penetrated into the port flange and configured
to suction air to form a degree of vacuum at a position different
from a position of the exhaust port.
In addition, a pump cap may be coupled to the port flange, and a
vane may be disposed in an internal space of the pump cap to rotate
the vane by a motor to form the degree of vacuum. The motor may be
disposed under the port flange and coupled with the vane by a motor
shaft. The motor may be coupled with a pump controller, and the
pump controller may be disposed under the motor to drive the motor.
In particular, the pump controller may be protected from the
outside by a pump cover coupled to a lower side of the pump
housing. The pump cover may include a connector port through which
a power supply and a signal line may be coupled to the pump
controller.
In accordance with an exemplary embodiment of the present
invention, a vacuum boosting brake system may include: an electric
vacuum pump including a watertight chamber having a water
containing capacity greater than a backflow water capacity of in an
internal space defined in a pump housing configured to form a
vacuum pressure, the watertight chamber being coupled to an exhaust
port of the pump housing; and a vacuum hose that couples a brake
booster with the electric vacuum pump. The vacuum hose may be
coupled to an intake port of the pump housing. The intake port may
include a check valve configured to unidirectionally form a vacuum
pressure in the vacuum hose.
As described above, an EVP applied to a vacuum boosting brake
system in accordance with the present invention may include a
watertight chamber and thus has the following operation and
effects. First, even when the EVP is installed at an engine
mounting position having insufficient watertightness, fluid may be
prevented from being undesirably drawn into the EVP. Second, a
motor failure due to insufficient watertightness of the EVP may be
prevented, whereby the entirety of a chassis controller coupled to
a chassis CAN may be prevented from malfunctioning.
Third, the snorkeling hose apparatus which has been used to prevent
fluid from being drawn into the EVP may be omitted, and thus, the
production cost may be reduced. Fourth, space may be secured by
removing the snorkeling hose apparatus, whereby there are
advantages in terms of a layout of an engine room. Fifth, the
watertight chamber has a volume greater than the amount of water
drawn by reverse rotation of the motor which occurs while the motor
stops, whereby regardless of a vehicle model and specifications of
a brake, the interior of the motor may be prevented from being
immersed in water due to reverse water suction of an outlet of the
EVP. Lastly, the watertight chamber may be changed in shape to have
an EVP-outlet integrated structure or a separate threaded coupling
structure depending on a layout of the engine room.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present
invention will be more clearly understood from the following
detailed description taken in conjunction with the accompanying
drawings, in which:
FIG. 1 is a diagram illustrating the configuration of a watertight
chamber type electric vacuum pump in accordance with an exemplary
embodiment of the present invention;
FIG. 2 is an assembly diagram of the electric vacuum pump to which
a watertight chamber is applied through a hose fitting assembly or
threaded assembly process, in accordance with an exemplary
embodiment of the present invention;
FIG. 3 is a diagram illustrating the operation of the watertight
chamber type electric vacuum pump in accordance with an exemplary
embodiment of the present invention;
FIG. 4 is a diagram illustrating a fluid permeation blocking state
of the watertight chamber when a motor of the watertight chamber
type electric vacuum pump is reversely rotated, in accordance with
an exemplary embodiment of the present invention; and
FIG. 5 is a diagram illustrating the configuration of a vacuum
boosting brake system to which the watertight chamber type electric
vacuum pump is applied, in accordance with an exemplary embodiment
of the present invention.
DETAILED DESCRIPTION
It is understood that the term "vehicle" or "vehicular" or other
similar term as used herein is inclusive of motor vehicles in
general such as passenger automobiles including sports utility
vehicles (SUV), buses, trucks, various commercial vehicles,
watercraft including a variety of boats and ships, aircraft, and
the like, and includes hybrid vehicles, electric vehicles,
combustion, plug-in hybrid electric vehicles, hydrogen-powered
vehicles and other alternative fuel vehicles (e.g. fuels derived
from resources other than petroleum).
Although exemplary embodiment is described as using a plurality of
units to perform the exemplary process, it is understood that the
exemplary processes may also be performed by one or plurality of
modules. Additionally, it is understood that the term
controller/control unit refers to a hardware device that includes a
memory and a processor. The memory is configured to store the
modules and the processor is specifically configured to execute
said modules to perform one or more processes which are described
further below.
The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof. As
used herein, the term "and/or" includes any and all combinations of
one or more of the associated listed items.
Unless specifically stated or obvious from context, as used herein,
the term "about" is understood as within a range of normal
tolerance in the art, for example within 2 standard deviations of
the mean. "About" can be understood as within 10%, 9%, 8%, 7%, 6%,
5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated
value. Unless otherwise clear from the context, all numerical
values provided herein are modified by the term "about."
Hereinafter, exemplary embodiments of the present invention will be
described in detail with reference to the attached drawings. These
exemplary embodiments are only for illustrative purposes and may be
modified in various forms by those with ordinary knowledge in this
art. Hence, the present invention is not limited to theses
exemplary embodiments.
Referring to FIG. 1, an electric vacuum pump 1 may include a
watertight chamber 10, a pump housing 20, a motor 30, a vane 40, a
pump controller 50, a sealing ring 60, a pump cap 70, a pump cover
80, and a connector port 90. Therefore, the electric vacuum pump 1
is characterized as a watertight chamber type electric vacuum
pump.
For example, the watertight chamber 10 may include a chamber body
11 and a connection port 13. The chamber body 11 may be formed as a
hollow tank open on one side thereof to allow the tank to be filled
with water. Particularly, a side surface of the chamber body 11 may
have an arc shape to allow the chamber body 11 to abut an outer
circumferential surface of a cylindrical housing body of the pump
housing 20. The connection port 13 may be coupled to an exhaust
port 25 of the pump housing 20 and thus may function as a passage
through which water is discharged from the pump housing 20 into the
watertight chamber 10 via the exhaust port 25.
Additionally, the pump housing 20 may be formed as the housing body
having an internal space which houses the motor 30, the vane 40,
and the pump controller 50. The pump housing 20 may be coupled to
the exhaust port 25 with the arc-shaped chamber body of the
watertight chamber 10 abutting the outer circumferential surface of
the housing body. Accordingly, a port flange 21 may be provided on
the pump housing 20. An intake port 23 and the exhaust port 25 may
be provided on the port flange 21. The intake port 23 may protrude
from a side surface of the port flange 21 and penetrate the port
flange 21.
The exhaust port 25 may penetrate the port flange 21 such that the
exhaust port 25 is inclined at a predetermined inclination angle in
the port flange 21. Hence, the exhaust port 25 may be configured to
discharge, to the outside, air drawn into the internal space of the
pump housing 20 through the intake port 23. In addition, the
exhaust port 25 may function as a passage through which stagnant
water or moisture in the electric vacuum pump 1 may be discharged
to the connection port 13 of the watertight chamber 10.
For example, the motor 30 may be a direct current (DC) type
electric motor which is operated by the pump controller 50. A motor
shaft 31 of the motor 30 may be coupled with the vane 40.
Particularly, the motor shaft 31 may form an airtight structure on
a junction with the vane 40. The pump controller 50 may include a
printed circuit board (PCB) with electric and control devices, and
may be disposed under the motor 30 and electrically coupled with
the motor 30 to adjust the rotation of the motor 30. The sealing
ring 60 may seal the motor 30 and the pump controller 50, thus
protecting an electric circuit of the pump controller 50 from
water.
For example, the pump cap 70 may be coupled to an upper side of the
pump housing 20 using the port flange 21 provided on the housing
body of the pump housing 20 to house or accommodate the vane 40
disposed over the pump housing 20 and protect the vane 40 from the
outside. Particularly, the pump cap 70 may form a seal with the
port flange 21 of the pump housing 20. The pump cover 80 may be
coupled to a lower side of the pump housing 20 using the housing
body of the pump housing 20, thus protecting a lower portion of the
pump housing 20 from the outside. The connector port 90 may couple
an external port supply, a signal line, etc. to the pump controller
50.
Referring to FIG. 2, the connection port 13 of the watertight
chamber 10 may have a bent structure. Particularly, an inclination
angle of the bent structure may be the same as the inclination
angle of the discharge port 25 of the pump housing 20. For example,
the connection port 13 may include a chamber port 15-1, and an
extension hose 17-1 having a bent structure relative to the chamber
port 15-1 to have an inclination angle about that same as that of
the exhaust port 25. In this case, the extension hose 17-1 may be
fitted into the exhaust port 25 of the pump housing 20 using a
planar outer circumferential surface of the extension hose 17-1.
Alternatively, the exhaust port 25 of the pump housing 20 may be
fitted into the extension hose 17-1. Accordingly, the exhaust port
25 may have an extension hose fitting depression into which the
extension hose 17-1 may be inserted, or may have a protruding boss
fitted into the extension hose 17-1.
In another example, the connection port 13 may include a chamber
port 15-1, and a threaded extension hose 17-2 having a bent
structure relative to the chamber port 15-1 to have an inclination
angle about the same as that of the exhaust port 25. The threaded
extension hose 17-2 may be threadedly coupled to the exhaust port
25 of the pump housing 20 using a threaded coupling structure.
Accordingly, the exhaust port 25 may further include a thread tap
having an internal thread that corresponds to an external thread of
the threaded extension hole 17-1.
Referring again to FIG. 2, the port flange 21 of the pump housing
20 separates the motor 30 from the vane 40, and draws air into
(e.g., suctions) the space in the pump cap 70 through the intake
port 23 and then discharges the air into the watertight chamber 10
through the exhaust port 25.
FIG. 3 illustrates an operation of generating vacuum suction force
by the vane 40 of the electric vacuum pump 1. As illustrated in the
drawing, the vane 40 may be rotated by the motor shaft 31 of the
motor 30 and may be configured to suction air through an intake
path 27 in communication with the intake port 23, and then
discharge, using the internal space of the pump cap 70 as a
discharge path 28, the air into the watertight chamber 10 through
an exhaust path 29 in communication with the exhaust port 25.
Therefore, the rotation of the vane 40 may perform an air intake
operation through the intake path 27, a closing operation of the
intake path 27, a transfer operation through the discharge path 28,
and an exhaust operation through the exhaust path 29, thus forming
vacuum pressure relative to an apparatus (e.g., a brake booster 120
of FIG. 5) coupled thereto.
FIG. 4 illustrates design conditions for the watertight chamber 10.
As illustrated in the drawing, three types of pressures {circle
around (a)}, {circle around (b)}, and {circle around (c)} separated
from each other may be generated in the electric vacuum pump 1. The
pressure {circle around (a)} may be generated during a period in
which the operation of the motor 30 stops, and may be formed to a
required value or more. The pressure {circle around (b)} may be
generated in the electric vacuum pump 1 and formed to a
predetermined value. The pressure {circle around (c)} may be
atmospheric pressure formed in the internal space of the watertight
chamber 10. For example, the pressures {circle around (a)} and
{circle around (b)} is about 500-700 mmHg respectively, the
pressures {circle around (c)} is about 760 mmHg.
Therefore, the intensities of vacuum by the pressures {circle
around (a)}, {circle around (b)}, and {circle around (c)} are as
follows. Relationship in the intensities of vacuum: pressure
{circle around (a)}>pressure {circle around (b)}>pressure
{circle around (c)}. Here, ">" is an inequality sign indicating
a relationship between two values. Accordingly, the pressure
{circle around (a)} is greater than the pressure {circle around
(b)}, and the pressure {circle around (b)} is greater than the
pressure {circle around (c)}. Hence, during the period in which the
operation of the motor 30 stops, water drawn from the watertight
chamber 10 may flow backward into the exhaust port 25 via the
connection port 13 and thus may be drawn into the vane 40, the
motor 30, and the pump controller 50.
However, the capacity of the watertight chamber 10 is greater than
the maximum amount of backflow water which flows backward into the
internal space of the electric vacuum pump 1 by reverse rotation of
the motor 30 when the motor 30 stops while a check valve 140 (refer
to FIG. 5) coupled to the intake port 23 of the electric vacuum
pump 1 is closed. Particularly, the maximum amount of backflow
water may be approximately 5 cc (ACC). Therefore, even when the
electric vacuum pump 1 draws water thereinto due to the degree of
vacuum generated by reverse rotation of the motor, the watertight
chamber 10 may retain the drawn water in the chamber body of the
watertight chamber 10 having a predetermined chamber capacity,
whereby the water may be prevented from flowing backward into the
exhaust port 25 via the connection port 13.
Referring to FIG. 5, a vacuum boosting brake system 100 may include
a watertight chamber type electric vacuum pump 1, and a brake
vacuum pressure apparatus (110, 120, 120-1, 130, and 140). In
particular, the watertight chamber type electric vacuum pump 1 may
include a watertight chamber 10 and thus has the same structure of
that of the watertight chamber type electric vacuum pump 10
described with reference to FIGS. 1 to 4. Therefore, the operation
of the watertight chamber type electric vacuum pump 1 may form
vacuum pressure for the brake booster 120 which is insufficient in
vacuum pressure.
However, there is a difference in that the watertight chamber type
electric vacuum pump 1 may include a check valve 140 to prevent the
degree of vacuum of the watertight chamber type electric vacuum
pump 1 from being transmitted to the brake booster 120 by coupling
the vacuum hose 130 of the brake vacuum pressure apparatus of the
pump housing 20. In an exemplary embodiment, the brake vacuum
pressure apparatus (110, 120, 120-1, 130, and 140) may include a
pedal 110, a brake booster 120, a negative pressure switch 120-1, a
vacuum hose 130, and a check valve 140.
For example, the pedal 110 is a brake pedal and may be connected
with the brake booster 120. The brake booster 120 may be configured
to boost pedal pressing force using vacuum pressure generated in
conjunction with an operation of pressing the pedal 110. The
negative pressure switch 120-1 (e.g., sensor) may be configured to
detect vacuum pressure of the brake booster 120 and transmit the
vacuum pressure to the pump controller 50 to generate information
for operating the motor 30. The vacuum hose 130 may couple the
brake booster 120 with the intake port 23 of the watertight chamber
type electric vacuum pump 1, thus functioning to supplement an
insufficient degree of vacuum of the brake booster 120 using the
operation of the motor 30. The check valve 140 may be applied to
the intake port 23 of the pump housing 20, which forms the
watertight chamber type electric vacuum pump 1, to form a
unidirectional flow of vacuum pressure to thus prevent the degree
of vacuum of the watertight chamber type electric vacuum pump 1
from being transmitted to the brake booster 120.
Therefore, the vacuum boosting brake system 100 may use all
advantages of the watertight chamber type electric vacuum pump 1.
For example, the advantages of the watertight chamber type electric
vacuum pump 1 are as follows.
First, the watertight chamber 10 prevents water from permeating
through the exhaust port 25 using the pressure of air which is
present in the chamber body while the electric vacuum pump is
immersed in water. Second, the chamber body has a capacity greater
than about 5 cc (ACC) that is the maximum suction amount of water
flowing backward due to reverse rotation of the motor 30 caused
when the operation of the motor 30 stops. Therefore, immersion in
water due to reverse water suction may be fundamentally
prevented.
Third, compared to a typical snorkeling hose, the watertight
chamber 10 provides advantages in terms of a layout, the material
cost, and the weight. Fourth, the watertight chamber 10 may be
modified into a separable watertight chamber 10 having a threaded
structure using the threaded extension hose 17-2 of the connection
port 13. Therefore, a change in shape of the watertight chamber 10
depending on the layout may be facilitated.
As described above, the electric vacuum pump 1 applied to the
vacuum boosting brake system 100 in according to an exemplary
embodiment of the present disclosure may have a water containing
capacity greater than a backflow water capacity of the internal
space defined in the pump housing 20 which forms vacuum pressured,
and may include the watertight chamber 10 coupled to the exhaust
port 25 of the pump housing 20.
Watertightness for the electric vacuum pump 1 which is installed at
an insufficient watertight position may be secured, and thus, the
typical snorkeling hose apparatus may be removed, whereby the
production cost and weight of the electric vacuum pump 1 may be
reduced. Particularly, the possibility of backflow water when the
operation of the motor 30 stops may be prevented by the water
chamber 10 having a sufficient water capacity. Therefore, the
internal electric circuit may be prevented from being damaged even
when the electric vacuum pump 1 is immersed in water.
While the present invention has been described with respect to the
exemplary embodiments, it will be apparent to those skilled in the
art that various changes and modifications may be made without
departing from the spirit and scope of the invention as defined in
the following claims.
* * * * *